From patchwork Tue Nov 19 16:12:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11252411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80FBF13A4 for ; Tue, 19 Nov 2019 16:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61C71223BD for ; Tue, 19 Nov 2019 16:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728470AbfKSQNF (ORCPT ); Tue, 19 Nov 2019 11:13:05 -0500 Received: from inva020.nxp.com ([92.121.34.13]:41658 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728471AbfKSQNE (ORCPT ); Tue, 19 Nov 2019 11:13:04 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 2A9AA1A046A; Tue, 19 Nov 2019 17:13:02 +0100 (CET) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 1CE2D1A0065; Tue, 19 Nov 2019 17:13:02 +0100 (CET) Received: from fsr-ub1864-112.ea.freescale.net (fsr-ub1864-112.ea.freescale.net [10.171.82.98]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 3B6BD203BF; Tue, 19 Nov 2019 17:13:01 +0100 (CET) From: Leonard Crestez To: Chanwoo Choi , Matthias Kaehlcke , "Rafael J. Wysocki" Cc: Kyungmin Park , MyungJoo Ham , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Saravana Kannan , Krzysztof Kozlowski , Alexandre Bailon , Georgi Djakov , Jacky Bai , Viresh Kumar , NXP Linux Team , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH RFC 1/2] PM / devfreq: Add PM QoS support Date: Tue, 19 Nov 2019 18:12:13 +0200 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Register notifiers with the PM QoS framework in order to respond to requests for DEV_PM_QOS_MIN_FREQUENCY and DEV_PM_QOS_MAX_FREQUENCY. No notifiers are added by this patch but PM QoS constraints can be imposed externally (for example from other devices). Signed-off-by: Leonard Crestez Acked-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 77 +++++++++++++++++++++++++++++++++++++++ include/linux/devfreq.h | 5 +++ 2 files changed, 82 insertions(+) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 65a4b6cf3fa5..34bbaac6ea7e 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -22,15 +22,18 @@ #include #include #include #include #include +#include #include "governor.h" #define CREATE_TRACE_POINTS #include +#define HZ_PER_KHZ 1000 + static struct class *devfreq_class; /* * devfreq core provides delayed work based load monitoring helper * functions. Governors can use these or can implement their own @@ -109,10 +112,11 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) static void get_freq_range(struct devfreq *devfreq, unsigned long *min_freq, unsigned long *max_freq) { unsigned long *freq_table = devfreq->profile->freq_table; + s32 qos_min_freq, qos_max_freq; lockdep_assert_held(&devfreq->lock); /* * Initialize minimum/maximum frequency from freq table. @@ -125,10 +129,20 @@ static void get_freq_range(struct devfreq *devfreq, } else { *min_freq = freq_table[devfreq->profile->max_state - 1]; *max_freq = freq_table[0]; } + /* Apply constraints from PM QoS */ + qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MIN_FREQUENCY); + qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MAX_FREQUENCY); + *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); + if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) + *max_freq = min(*max_freq, + (unsigned long)HZ_PER_KHZ * qos_max_freq); + /* Apply constraints from sysfs */ *min_freq = max(*min_freq, devfreq->min_freq); *max_freq = min(*max_freq, devfreq->max_freq); /* Apply constraints from OPP interface */ @@ -624,29 +638,80 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, err); return NOTIFY_OK; } +/** + * qos_notifier_call() - Common handler for QoS constraints. + * @devfreq: the devfreq instance. + */ +static int qos_notifier_call(struct devfreq *devfreq) +{ + int err; + + mutex_lock(&devfreq->lock); + err = update_devfreq(devfreq); + mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from PM QoS (%d)\n", + err); + + return NOTIFY_OK; +} + +/** + * qos_min_notifier_call() - Callback for QoS min_freq changes. + * @nb: Should be devfreq->nb_min + */ +static int qos_min_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); +} + +/** + * qos_max_notifier_call() - Callback for QoS max_freq changes. + * @nb: Should be devfreq->nb_max + */ +static int qos_max_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); +} + /** * devfreq_dev_release() - Callback for struct device to release the device. * @dev: the devfreq device * * Remove devfreq from the list and release its resources. */ static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); + int err; mutex_lock(&devfreq_list_lock); if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { mutex_unlock(&devfreq_list_lock); dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); return; } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove max_freq notifier: %d\n", err); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove min_freq notifier: %d\n", err); + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); mutex_destroy(&devfreq->lock); kfree(devfreq); @@ -764,10 +829,22 @@ struct devfreq *devfreq_add_device(struct device *dev, srcu_init_notifier_head(&devfreq->transition_notifier_list); mutex_unlock(&devfreq->lock); + devfreq->nb_min.notifier_call = qos_min_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err) + goto err_devfreq; + + devfreq->nb_max.notifier_call = qos_max_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err) + goto err_devfreq; + mutex_lock(&devfreq_list_lock); governor = try_then_request_governor(devfreq->governor_name); if (IS_ERR(governor)) { dev_err(dev, "%s: Unable to find governor for the device\n", diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 2bae9ed3c783..8b92ccbd1962 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -134,10 +134,12 @@ struct devfreq_dev_profile { * @total_trans: Number of devfreq transitions * @trans_table: Statistics of devfreq transitions * @time_in_state: Statistics of devfreq states * @last_stat_updated: The last time stat updated * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier + * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY + * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY * * This structure stores the devfreq information for a give device. * * Note that when a governor accesses entries in struct devfreq in its * functions except for the context of callbacks defined in struct @@ -176,10 +178,13 @@ struct devfreq { unsigned int *trans_table; unsigned long *time_in_state; unsigned long last_stat_updated; struct srcu_notifier_head transition_notifier_list; + + struct notifier_block nb_min; + struct notifier_block nb_max; }; struct devfreq_freqs { unsigned long old; unsigned long new; From patchwork Tue Nov 19 16:12:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11252413 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BE901930 for ; Tue, 19 Nov 2019 16:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7B19223AC for ; Tue, 19 Nov 2019 16:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728471AbfKSQNF (ORCPT ); Tue, 19 Nov 2019 11:13:05 -0500 Received: from inva020.nxp.com ([92.121.34.13]:41698 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728474AbfKSQNF (ORCPT ); Tue, 19 Nov 2019 11:13:05 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 34D361A0456; Tue, 19 Nov 2019 17:13:03 +0100 (CET) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 268341A0406; Tue, 19 Nov 2019 17:13:03 +0100 (CET) Received: from fsr-ub1864-112.ea.freescale.net (fsr-ub1864-112.ea.freescale.net [10.171.82.98]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 349AC203BF; Tue, 19 Nov 2019 17:13:02 +0100 (CET) From: Leonard Crestez To: Chanwoo Choi , Matthias Kaehlcke , "Rafael J. Wysocki" Cc: Kyungmin Park , MyungJoo Ham , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Saravana Kannan , Krzysztof Kozlowski , Alexandre Bailon , Georgi Djakov , Jacky Bai , Viresh Kumar , NXP Linux Team , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH RFC 2/2] PM / devfreq: Use PM QoS for sysfs min/max_freq Date: Tue, 19 Nov 2019 18:12:14 +0200 Message-Id: <1f567d6478b1782f7f4afc27cb6d3f896d77ac9f.1574179738.git.leonard.crestez@nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Switch the handling of min_freq and max_freq from sysfs to use the dev_pm_qos_request interface. Since PM QoS handles frequencies as kHz this change reduces the precision of min_freq and max_freq. This shouldn't introduce problems because frequencies which are not an integer number of kHz are likely not an integer number of Hz either. Try to ensure compatibility by rounding min values down and rounding max values up. Signed-off-by: Leonard Crestez Acked-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 76 ++++++++++++++++++++++++++++++--------- include/linux/devfreq.h | 9 ++--- 2 files changed, 64 insertions(+), 21 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 34bbaac6ea7e..518dd2745d06 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -139,14 +139,10 @@ static void get_freq_range(struct devfreq *devfreq, *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) *max_freq = min(*max_freq, (unsigned long)HZ_PER_KHZ * qos_max_freq); - /* Apply constraints from sysfs */ - *min_freq = max(*min_freq, devfreq->min_freq); - *max_freq = min(*max_freq, devfreq->max_freq); - /* Apply constraints from OPP interface */ *min_freq = max(*min_freq, devfreq->scaling_min_freq); *max_freq = min(*max_freq, devfreq->scaling_max_freq); if (*min_freq > *max_freq) @@ -708,10 +704,23 @@ static void devfreq_dev_release(struct device *dev) DEV_PM_QOS_MIN_FREQUENCY); if (err && err != -ENOENT) dev_warn(dev->parent, "Failed to remove min_freq notifier: %d\n", err); + if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove max_freq request: %d\n", err); + } + if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove min_freq request: %d\n", err); + } + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); mutex_destroy(&devfreq->lock); kfree(devfreq); @@ -780,19 +789,17 @@ struct devfreq *devfreq_add_device(struct device *dev, if (!devfreq->scaling_min_freq) { mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } - devfreq->min_freq = devfreq->scaling_min_freq; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } - devfreq->max_freq = devfreq->scaling_max_freq; devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); atomic_set(&devfreq->suspend_count, 0); dev_set_name(&devfreq->dev, "devfreq%d", @@ -829,10 +836,20 @@ struct devfreq *devfreq_add_device(struct device *dev, srcu_init_notifier_head(&devfreq->transition_notifier_list); mutex_unlock(&devfreq->lock); + err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, + DEV_PM_QOS_MIN_FREQUENCY, 0); + if (err < 0) + goto err_devfreq; + err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, + DEV_PM_QOS_MAX_FREQUENCY, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); + if (err < 0) + goto err_devfreq; + devfreq->nb_min.notifier_call = qos_min_notifier_call; err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, DEV_PM_QOS_MIN_FREQUENCY); if (err) goto err_devfreq; @@ -1414,18 +1431,26 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, { struct devfreq *df = to_devfreq(dev); unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_min_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - df->min_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + /* Round down to kHz for PM QoS */ + ret = dev_pm_qos_update_request(&df->user_min_freq_req, + value / HZ_PER_KHZ); + if (ret < 0) + return ret; return count; } static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, @@ -1446,22 +1471,39 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, { struct devfreq *df = to_devfreq(dev); unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_max_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - - if (!value) - value = ULONG_MAX; + /* + * PM QoS frequencies are in kHz so we need to convert. Convert by + * rounding upwards so that the acceptable interval never shrinks. + * + * For example if the user writes "666666666" to sysfs this value will + * be converted to 666667 kHz and back to 666667000 Hz before an OPP + * lookup, this ensures that an OPP of 666666666Hz is still accepted. + * + * A value of zero means "no limit". + */ + if (value) + value = DIV_ROUND_UP(value, HZ_PER_KHZ); + else + value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; - df->max_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); + if (ret < 0) + return ret; return count; } static DEVICE_ATTR_RW(min_freq); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 8b92ccbd1962..fb376b5b7281 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -11,10 +11,11 @@ #define __LINUX_DEVFREQ_H__ #include #include #include +#include #define DEVFREQ_NAME_LEN 16 /* DEVFREQ governor name */ #define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand" @@ -121,12 +122,12 @@ struct devfreq_dev_profile { * devfreq.nb to the corresponding register notifier call chain. * @work: delayed work for load monitoring. * @previous_freq: previously configured frequency value. * @data: Private data of the governor. The devfreq framework does not * touch this. - * @min_freq: Limit minimum frequency requested by user (0: none) - * @max_freq: Limit maximum frequency requested by user (0: none) + * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) + * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. * @suspend_freq: frequency of a device set during suspend phase. * @resume_freq: frequency of a device set in resume phase. @@ -161,12 +162,12 @@ struct devfreq { unsigned long previous_freq; struct devfreq_dev_status last_status; void *data; /* private data for governors */ - unsigned long min_freq; - unsigned long max_freq; + struct dev_pm_qos_request user_min_freq_req; + struct dev_pm_qos_request user_max_freq_req; unsigned long scaling_min_freq; unsigned long scaling_max_freq; bool stop_polling; unsigned long suspend_freq;